The subject invention is directed toward the art of pipe joints and couplings and, more particularly, to a fitting construction for connecting corrugated tubing to associated structure.
The invention is particularly suited for use with plastic corrugated tubing of the type used as electrical conduit and will be described with reference thereto; however, as will become apparent, the invention could be used with other types of tubing used for other purposes.
Corrugated and non-corrugated thermoplastic tubing is widely used as electrical conduit for protecting wiring and cables extending between various control boxes, switch boxes, and the like. To facilitate the use and installation of such tubing it has been desirable to provide push together or "snap together" type connectors which allow the tubing sections to be joined to each other or to system components quickly and without requiring special tools or adhesives.
A wide variety of different connector designs have been proposed for this purpose. These prior connector designs have varied from extremely simple one piece types using simple resilient tabs or fingers to complex multi-component designs using multiple swaged rings or other internal connector elements.
Although the simpler one-piece designs are typically the most desirable from the standpoint of manufacturing and use, it has generally been necessary to use expensive plastics in their manufacture in order to achieve the necessary strengths and resistance to pull-out. Accordingly, there has been a need for a simplified fitting design which is easy to manufacture and use, and which does not require the use of expensive materials or extremely complex molds and dies.